100 research outputs found
Supervised exercise training in patients with cancer during anthracycline-based chemotherapy to mitigate cardiotoxicity: a randomized-controlled-trial
Background: Exercise training (ET) has been shown to mitigate cardiotoxicity of anthracycline-based chemotherapies (AC) in animal models. Data from randomized controlled trials in patients with cancer are sparse.
Methods: Patients with breast cancer or lymphoma receiving AC were recruited from four cancer centres and randomly assigned to 3 months supervised ET. Primary outcome was change in left ventricular global longitudinal strain (GLS) from baseline (before AC) to post AC (AC-end) compared between the EXduringAC group, who participated in an exercise intervention during AC including the provision of an activity tracker, and the control group EXpostAC, who received an activity tracker only. Secondary outcome parameters were changes in high sensitivity Troponin T (hsTnT), NT-pro-brain natriuretic peptide (NT-proBNP), peak oxygen consumption (peak VO2) and objectively measured physical activity (PA) during this same time-period. All assessments were repeated at a 12-week follow-up from AC-end, when also the EXpostAC group had completed the ET, that started after AC. In exploratory analyses, robust linear models were performed to assess the association of PA with changes in echocardiographic parameters and biomarkers of LV function.
Results: Fifty-seven patients (median age 47 years; 95% women) were randomized to EXduringAC (n = 28) and EXpostAC (n = 29) group. At AC-end, GLS deteriorated in both study groups (albeit insignificantly) with 7.4% and 1.0% in EXduringAC (n = 18) and EXpostAC (n = 18), respectively, and hsTnT and NT-proBNP significantly increased in both groups, without difference between groups for any parameter. Change in peak VO2 (−1.0 and −1.1 ml/kg/min) at AC-end was also similar between groups as was duration of moderate-to-vigorous PA (MVPA) with a median of 33 [26, 47] min/day and 32 [21, 59] min/day in the EXduringAC and EXpostAC group, respectively. In the robust linear model including the pooled patient population, MVPA was significantly associated with a more negative GLS and lesser increase in hsTnT at AC-end.
Conclusion: In this small scale RCT, supervised ET during AC was not superior to wearing a PA tracker to mitigate cardiotoxicity. The dose-response relationship between PA and cardioprotective effects during AC found in our and previous data supports the notion that PA should be recommended to patients undergoing AC.
Clinical Trial Registration: ClinicalTrials.gov, identifier NCT03850171
Complete experimental toolbox for alignment-free quantum communication
Quantum communication employs the counter-intuitive features of quantum
physics to perform tasks that are im- possible in the classical world. It is
crucial for testing the foundations of quantum theory and promises to rev-
olutionize our information and communication technolo- gies. However, for two
or more parties to execute even the simplest quantum transmission, they must
establish, and maintain, a shared reference frame. This introduces a
considerable overhead in communication resources, par- ticularly if the parties
are in motion or rotating relative to each other. We experimentally demonstrate
how to circumvent this problem with the efficient transmission of quantum
information encoded in rotationally invariant states of single photons. By
developing a complete toolbox for the efficient encoding and decoding of
quantum infor- mation in such photonic qubits, we demonstrate the fea- sibility
of alignment-free quantum key-distribution, and perform a proof-of-principle
alignment-free entanglement distribution and violation of a Bell inequality.
Our scheme should find applications in fundamental tests of quantum mechanics
and satellite-based quantum communication.Comment: Main manuscript: 7 pages, 3 figures; Supplementary Information: 7
pages, 3 figure
Late stages of the evolution of A-type stars on the main sequence: comparison between observed chemical abundances and diffusion models for 8 Am stars of the Praesepe cluster
Aims. We aim to provide observational constraints on diffusion models that
predict peculiar chemical abundances in the atmospheres of Am stars. We also
intend to check if chemical peculiarities and slow rotation can be explained by
the presence of a weak magnetic field.
Methods. We have obtained high resolution, high signal-to-noise ratio spectra
of eight previously-classified Am stars, two normal A-type stars and one Blue
Straggler, considered to be members of the Praesepe cluster. For all of these
stars we have determined fundamental parameters and photospheric abundances for
a large number of chemical elements, with a higher precision than was ever
obtained before for this cluster. For seven of these stars we also obtained
spectra in circular polarization and applied the LSD technique to constrain the
longitudinal magnetic field.
Results. No magnetic field was detected in any of the analysed stars. HD
73666, a Blue Straggler previously considered as an Ap (Si) star, turns out to
have the abundances of a normal A-type star. Am classification is not confirmed
for HD 72942. For HD 73709 we have also calculated synthetic Delta-a photometry
that is in good agreement with the observations. There is a generally good
agreement between abundance predictions of diffusion models and values that we
have obtained for the remaining Am stars. However, the observed Na and S
abundances deviate from the predictions by 0.6 dex and >0.25 dex respectively.
Li appears to be overabundant in three stars of our sample.Comment: Accepted for publication on A&
Mixing at young ages: Beryllium abundances in cool main-sequence stars of the open clusters IC 2391 and IC 2602
The determination of lithium abundances in stars of young clusters have shown
that they deplete Li by different degrees during their pre-main sequence phase.
Beryllium abundances are complementary to the lithium ones, and can help
tracing the mixing processes in the stellar interiors. Our aim is to derive
beryllium abundances in a sample of G- and K-type stars of two young pre-main
sequence open clusters, IC 2391 and IC 2602. The Be abundances are used to
investigate the mixing of internal material in these stars. The reliability of
the Be lines as abundance indicators in low-temperatures is also investigated
in detail. We derived Be abundances from high-resolution, high signal-to-noise
UVES/VLT spectra using spectrum synthesis and model atmospheres. Atmospheric
parameters and other elemental abundances are adopted from a previous work. The
sample stars have masses in the range between 0.80 < M/Msun < 1.20. They have
been shown to differ in lithium abundance by about 0.60 dex, with lower A(Li)
in cooler and lower mass stars. Here, we find that all the stars have the same
Be abundance within the uncertainties. These observations show that the Be
abundance is not affected by the mixing events in the pre-main sequence, in
this mass range, in agreement with the expectation of evolutionary models. A
comparison with Be abundances in older clusters shows that, contrary to the
models, cool stars deplete Be during their main-sequence lifetime, confirming
what has been previously suggested in the literature.Comment: To appear in A&A, 12 pages, 12 figure
HD 210111: a new lambda Bootis type SB system
The small group of lambda Bootis stars comprises late B to early F-type
stars, with moderate to extreme (up to a factor 100) surface underabundances of
most Fe-peak elements and solar abundances of lighter elements (C, N, O, and
S). The main mechanisms responsible for this phenomenon are atmospheric
diffusion, meridional mixing and accretion of material from their surroundings.
Especially spectroscopic binary (SB) systems with lambda Bootis type components
are very important to investigate the evolutionary status and accretion process
in more details. For HD 210111, also delta Scuti type pulsation was found which
gives the opportunity to use the tools of asteroseismology for further
investigations. The latter could result in strict constraints for the amount of
diffusion for this star. Together with models for the accretion and its source
this provides a unique opportunity to shed more light on these important
processes. We present classification and high resolution spectra for HD 210111.
A detailed investigation of the most likely combinations of single star
components was performed. For this, composite spectra with different stellar
astrophysical parameters were calculated and compared to the observations to
find the best fitting combination. HD 210111 comprises two equal (within the
estimated errors) stars with T(eff)=7400K, logg=3.8dex, [M/H]=-1.0dex and
vsini=30km/s. This result is in line with other strict observational facts
published so far for this object. It is only the third detailed investigated
lambda Bootis type SB system, but the first one with a known IR-excess.Comment: 5 pages, 2 figure
Cataclysmic Variables from Sloan Digital Sky Survey V -- the search for period bouncers continues
SDSS-V is carrying out a dedicated survey for white dwarfs, single and in
binaries, and we report the analysis of the spectroscopy of cataclysmic
variables (CVs) and CV candidates obtained during the final plug plate
observations of SDSS. We identify eight new CVs, spectroscopically confirm 53
and refute eleven published CV candidates, and we report 21 new or improved
orbital periods. Combined with previously published data, the orbital period
distribution of the SDSS-V CVs does not clearly exhibit a period gap. This is
consistent with previous findings that spectroscopically identified CVs have a
larger proportion of short-period systems compared to samples identified from
photometric variability. Remarkably, despite a systematic search, we find very
few period bouncers. We estimate the space density of period bouncers to be
, i.e. they represent only a few per
cent of the total CV population. This suggests that during their final phase of
evolution, CVs either destroy the donor, e.g. via a merger, or that they become
detached and cease mass transfer.Comment: Submitted to MNRA
Climate change drives microevolution in a wild bird
To ensure long-term persistence, organisms must adapt to climate change, but an evolutionary response to a quantified selection pressure driven by climate change has not been empirically demonstrated in a wild population. Here, we show that pheomelanin-based plumage colouration in tawny owls is a highly heritable trait, consistent with a simple Mendelian pattern of brown (dark) dominance over grey (pale). We show that strong viability selection against the brown morph occurs, but only under snow-rich winters. As winter conditions became milder in the last decades, selection against the brown morph diminished. Concurrent with this reduced selection, the frequency of brown morphs increased rapidly in our study population during the last 28 years and nationwide during the last 48 years. Hence, we show the first evidence that recent climate change alters natural selection in a wild population leading to a microevolutionary response, which demonstrates the ability of wild populations to evolve in response to climate change
Systematic Inference of Copy-Number Genotypes from Personal Genome Sequencing Data Reveals Extensive Olfactory Receptor Gene Content Diversity
Copy-number variations (CNVs) are widespread in the human genome, but comprehensive assignments of integer locus copy-numbers (i.e., copy-number genotypes) that, for example, enable discrimination of homozygous from heterozygous CNVs, have remained challenging. Here we present CopySeq, a novel computational approach with an underlying statistical framework that analyzes the depth-of-coverage of high-throughput DNA sequencing reads, and can incorporate paired-end and breakpoint junction analysis based CNV-analysis approaches, to infer locus copy-number genotypes. We benchmarked CopySeq by genotyping 500 chromosome 1 CNV regions in 150 personal genomes sequenced at low-coverage. The assessed copy-number genotypes were highly concordant with our performed qPCR experiments (Pearson correlation coefficient 0.94), and with the published results of two microarray platforms (95–99% concordance). We further demonstrated the utility of CopySeq for analyzing gene regions enriched for segmental duplications by comprehensively inferring copy-number genotypes in the CNV-enriched >800 olfactory receptor (OR) human gene and pseudogene loci. CopySeq revealed that OR loci display an extensive range of locus copy-numbers across individuals, with zero to two copies in some OR loci, and two to nine copies in others. Among genetic variants affecting OR loci we identified deleterious variants including CNVs and SNPs affecting ∼15% and ∼20% of the human OR gene repertoire, respectively, implying that genetic variants with a possible impact on smell perception are widespread. Finally, we found that for several OR loci the reference genome appears to represent a minor-frequency variant, implying a necessary revision of the OR repertoire for future functional studies. CopySeq can ascertain genomic structural variation in specific gene families as well as at a genome-wide scale, where it may enable the quantitative evaluation of CNVs in genome-wide association studies involving high-throughput sequencing
Internationalisation in Higher Education as a catalyst to STEAM
Internationalisation efforts in Higher Education are usually led by the institutions' International Offices in partnership with the academic units at various levels, thus providing an ideal opportunity to promote collaboration across colleges, schools and departments, and to bring staff with a broad range of experience and expertise to work together. This chapter discusses two ways in which Higher Education institutions can take advantage of these internationalisation efforts to cultivate and nurture STEAM. First, considering internationalisation of the curriculum (IoC) across disciplines, which entails the incorporation of 'an intercultural dimension into the content of the curriculum as well as the teaching and learning processes and support services of a programme of study' (Leask 2015). Inasmuch as IoC seeks to develop students' international and intercultural perspectives as global professionals and citizens, it requires engagement with the arts, humanities, social sciences and sustainability initiatives across programmes, providing an opportunity to embed STEAM in the curriculum. Further, I argue that there is a parallelism between the national cultures that IoC seeks to draw from and the disciplines themselves, which are also different cultures, 'separate communities of practice with their own organisations, power hierarchies, questions to answer and [sometimes heavily policed] entry boundaries' (Brown and Harris 2014, 115). An interdisciplinary approach, and in particular one that promotes STEAM, should enrich the curriculum and increase its relevance in the same way that an international approach would. And second, through matching an employability and transferable skills training programme across disciplines to the 'internationalisation at home' initiatives that seek to deploy international students and staff as resources in Higher Education institutions (Altbach and Yudkevich 2017). Such a programme would focus on bringing skills traditionally associated with the arts and humanities - such as aesthetic appreciation, critical thinking or communication skills - to students of technology and science, while also bringing skills traditionally associated with science and technology - such as planning and problem solving, numeracy and the use of information technology - to students of arts and humanities, actively taking advantage of the innovative perspectives that international staff and students bring. In sum, the chapter argues that the internationalisation agenda in Higher Education partly inherently overlaps with that of STEAM cultivation, and highlights two practical ways in which curricula can be modified to promote the latter while advancing the former for a more inclusive student experience, enhancing employability skills and promoting the interdisciplinary outlook to the most pressing wicked problems that societies so badly need today
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